//The headers

#include "SDL/SDL.h"
#include "SDL/SDL_image.h"
#include "SDL/SDL_ttf.h"
#include <string>

//Screen attributes
const int SCREEN_WIDTH = 640;
const int SCREEN_HEIGHT = 480;
const int SCREEN_BPP = 32;

//The surfaces
SDL_Surface *background = NULL;
SDL_Surface *up = NULL;
SDL_Surface *down = NULL;
SDL_Surface *left = NULL;
SDL_Surface *right = NULL;
SDL_Surface *screen = NULL;

//The event structure
SDL_Event event;

//The font
TTF_Font *font = NULL;

//The color of the font
SDL_Color textColor = { 0, 0, 0 };

SDL_Surface *load_image( std::string filename )
{
  //The image that's loaded
  SDL_Surface* loadedImage = NULL;

  //The optimized surface that will be used
  SDL_Surface* optimizedImage = NULL;

  //Load the image
  loadedImage = IMG_Load( filename.c_str() );

  //If the image loaded
  if( loadedImage != NULL )
    {
      //Create an optimized surface
      optimizedImage = SDL_DisplayFormat( loadedImage );

      //Free the old surface
      SDL_FreeSurface( loadedImage );

      //If the surface was optimized
      if( optimizedImage != NULL )
        {
	  //Color key surface
	  SDL_SetColorKey( optimizedImage, SDL_SRCCOLORKEY, SDL_MapRGB( optimizedImage->format, 0, 0xFF, 0xFF ) );
        }
    }

  //Return the optimized surface
  return optimizedImage;
}

void apply_surface( int x, int y, SDL_Surface* source, SDL_Surface* destination, SDL_Rect* clip = NULL )
{
  //Holds offsets
  SDL_Rect offset;

  //Get offsets
  offset.x = x;
  offset.y = y;

  //Blit
  SDL_BlitSurface( source, clip, destination, &offset );
}

bool init()
{
  //Initialize all SDL subsystems
  if( SDL_Init( SDL_INIT_EVERYTHING ) == -1 )
    {
      return false;
    }

  //Set up the screen
  screen = SDL_SetVideoMode( SCREEN_WIDTH, SCREEN_HEIGHT, SCREEN_BPP, SDL_SWSURFACE );

  //If there was an error in setting up the screen
  if( screen == NULL )
    {
      return false;
    }

  //Initialize SDL_ttf
  if( TTF_Init() == -1 )
    {
      return false;
    }

  //Set the window caption
  SDL_WM_SetCaption( "Press an Arrow Key", NULL );

  //If everything initialized fine
  return true;
}

bool load_files()
{
  //Load the background image
  background = load_image( "../../media/background.png" );

  //Open the font
  font = TTF_OpenFont( "../../media/lazy.ttf", 72 );

  //If there was a problem in loading the background
  if( background == NULL )
    {
      return false;
    }

  //If there was an error in loading the font
  if( font == NULL )
    {
      return false;
    }

  //If everything loaded fine
  return true;
}

void clean_up()
{
  //Free the surfaces
  SDL_FreeSurface( background );
  SDL_FreeSurface( up );
  SDL_FreeSurface( down );
  SDL_FreeSurface( left );
  SDL_FreeSurface( right );

  //Close the font
  TTF_CloseFont( font );

  //Quit SDL_ttf
  TTF_Quit();

  //Quit SDL
  SDL_Quit();
}
int main( int argc, char* args[] )
{
  //Quit flag
  bool quit = false;

  //Initialize
  if( init() == false )
    {
      return 1;
    }

  //Load the files
  if( load_files() == false )
    {
      return 1;
    }

  //Render the text
  up = TTF_RenderText_Solid( font, "Up", textColor );
  down = TTF_RenderText_Solid( font, "Down", textColor );
  left = TTF_RenderText_Solid( font, "Left", textColor );
  right = TTF_RenderText_Solid( font, "Right", textColor );

  //While the user hasn't quit
  while( quit == false )
    {
      //While there's events to handle
      while( SDL_PollEvent( &event ) )
        {
	  //If the user has Xed out the window
	  if( event.type == SDL_QUIT )
            {
	      //Quit the program
	      quit = true;
            }
        }

      //Apply the background
      apply_surface( 0, 0, background, screen );

      //Get the keystates
      Uint8 *keystates = SDL_GetKeyState( NULL );

      //If up is pressed
      if( keystates[ SDLK_UP ] )
        {
	  apply_surface( ( SCREEN_WIDTH - up->w ) / 2, ( SCREEN_HEIGHT / 2 - up->h ) / 2, up, screen );
        }

      //If down is pressed
      if( keystates[ SDLK_DOWN ] )
        {
	  apply_surface( ( SCREEN_WIDTH - down->w ) / 2, ( SCREEN_HEIGHT / 2 - down->h ) / 2 + ( SCREEN_HEIGHT / 2 ), down, screen );
        }

      //If left is pressed
      if( keystates[ SDLK_LEFT ] )
        {
	  apply_surface( ( SCREEN_WIDTH / 2 - left->w ) / 2, ( SCREEN_HEIGHT - left->h ) / 2, left, screen );
        }

      //If right is pressed
      if( keystates[ SDLK_RIGHT ] )
        {
	  apply_surface( ( SCREEN_WIDTH / 2 - right->w ) / 2 + ( SCREEN_WIDTH / 2 ), ( SCREEN_HEIGHT - right->h ) / 2, right, screen );
        }

      //Update the screen
      if( SDL_Flip( screen ) == -1 )
        {
	  return 1;
        }
    }

  //Clean up
  clean_up();

  return 0;
}
